The U.S. Capitol building can be seen from behind high security measures in Washington, U.S., January 25, 2021. REUTERS/Leah Millis WASHINGTON (Reuters) - Top U.S. Capitol security officials apologised on Tuesday for "failings" during the deadly attack on the building by followers of then-President Donald Trump in a bid to stop the certification of Joe Biden's election victory. The officials specifically acknowledged a number of missteps: conflicting intelligence, inadequate preparation and insufficient mobilization of partner agencies, and called for improving accountability systems and communications structures. "I am here to offer my sincerest apologies on behalf of the Department," said Yolanda Pittman, the acting chief of Capitol Police, according to a prepared statement for the U.S. House of Representatives' Appropriations Committee.